Effects of fluorine on cyclosilazanes and cyclic silylhydrazines

Abstract

Compared with organic-substituted cyclosilazanes only a few Si-N ring systems with inorganic substituents are known. They differ very much in molecular structure and reaction behaviour. We succeeded in the synthesis of the first (F2SiN-) cyclodi- and cyclotrisilazanes. Standard molecular orbital ab initio calculations for several cyclosilazanes were carried out for the parent cyclodisilazane, the tetrafluoro-substituted cyclodisilazane, the disilyl-substituted cyclodisilazane, and the disilyl-, tetrafluoro-substituted cyclodisilazane in order to provide a rationalisation for the very short Si...Si distance in the isolated cyclodisilazanes.